The present invention relates to electrostatic precipitators and, more particularly, to segmented collecting electrode panels comprised of a plurality of individual collecting electrode plates suspended from a support beam.
In the operation of an electrostatic precipitator, a gas laden with entrained particulate material will pass through an electrostatic field established about a discharge electrode assembly disposed intermediate to grounded collecting electrode panels. The suspended particles become electrically charged as they pass through the electrostatic field and move to, under the influence of the electrostatic field, and deposit upon the grounded collecting electrode panels flanking the discharge electrode assembly.
Although the prior art includes various collecting electrode panel designs, collecting electrode panels are commonly constructed in modular form by suspending a plurality of successively aligned collecting electrode plates in end to end relationship to form the collecting electrode panel. Each collecting electrode plate is typically suspended from a support beam mounted in the top of the precipitator housing to extend downwardly in a vertical plane. Each individual plate is formed of sheet metal and typically ranges from 1 to 3 feet in width and typically from 30 to 50 feet in length. One common configuration of collecting electrode plate is shown in U.S. Pat. No. 4,240,810. As disclosed therein, each panel includes a central flat plate web portion extending between spaced end portions which comprise J-shaped stiffening beams.
It has been common practice in the prior art to suspend the collecting electrode plates from the support beam by means of fasteners, such as pins or bolts, which extend transversely through the collecting electrode plates into the support beam or into a support lug mounted to the support beam. In either case, the ends of the fasteners would extend perpendicularly outwardly beyond the extremities of the collecting electrode plates. As a minimum distance must be maintained between the discharge electrode assembly and the nearest point of the collecting electrode assembly, the extension of the fastener means beyond the extremity of the plane of the collecting electrode plate results in a spacing between the collecting electrode assembly and the discharge electrode assembly being set such that the end of the fastener means is beyond the minimum distance. Therefore, the spacing that actually exists between the collecting electrode panel and the discharge electrode assembly is greater than that required to prevent electrical spark-over between the electrodes themselves in order to avoid electrical spark-over between the discharged electrode and the ends of the fastener means utilized to link the collecting electrode plates to the support beam. Thus, the precipitator housing is, in effect, oversized in order to accommodate the necessary increase in spacing in order to prevent spark-over between the discharge electrodes and the ends of the fastener means.